Magnetic device for use in alternating-current circuits.



No. 685,431. Patented get. 29, 1901.

THE mama PETERS co Pno'rmm'nu, WASHINGTON. n. c

UNITED STATES PATENT OFFICE.

JOHN PEARSON, OF ST. PAUL, MINNESOTA, AS SIGNOR OF ONE-HALF 'lO JAS. F.WILLIAMSON, OF MINNEAPOLIS, MINNESOTA.

MAGNETIC DEVICE FOR USE IN ALTERNATlNG-CURRENT CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 685,431, dated October29, 1901.

Application filed February 19, 1901. Serial No. 47,984. (No model.)

To all whom it may concern:

Be it known that 1, JOHN PEARSON, a citizen of the United States,residing at St. Paul, in the county of Ramsey and State of Minnesota,have invented certain new and useful Improvements in Magnetic Devicesfor Use in Alternating-Current Circuits; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same. v My invention relates to magnetic devices. It isespecially designed for use in alternatingcurrent circuits, but may alsobe employed in direct-current circuits.

The invention consists of the novel devices and combinations of deviceshereinafter described, and defined in the claims.

The invention is illustrated in the accompanying drawings, wherein likenotations refer to like parts throughout the several views. v In saiddrawings, Figure 1 is a View chiefly in elevation, but with some partsshown in section, illustrating one form of my device as applied forcontrolling an auxiliary circuit. Fig. 2 is a detail showing the minormagnet of the form illustrated in Fig. 1 detached. Fig. 3 is a View indiagram illustrating a modification wherein the minor magnet is in theform of an electromagnet and is shunt-connected into the same circuit asthe main magnet. Fig. 4 is a View similar to Fig. 3, but showing theminor magnet direct-connected in series with the main magnet.

Referring to Fig. 1, the mainmagnet 1 is shown as mounted on a suitablesupport 2 and as provided with an adjustable core adapted to be variablyset by a set-screw 3 in any desired adj ustmcnt relative to the pivotedarmature-lever 4. The conductors for the main magnet 1 are marked withthe common numeral 5 within the magnetic field of the inain magnet 1-,and on the opposite side of the armature-lever 4 is suitably mounted aminor magnet in position to act in opposition to the main magnet on saidarmaturelever 4c coincidently with the action thereon of the mainmagnet;

the support and provided with a lock-nut 8.

This little piece 6 of soft iron being located within the field of themain magnet 1, as noted, will become magnetized by induction from themain magnet and the magnetic forces in the two magnets will be in stepwith each other. Hence the minor magnet will act on the armature-lever 4in opposition to the main magnet coincidently with the action of themain magnet and will hold said armature-lever in its retracted positionuntil the main magnet has been energized up to a point where its liftingeffect exceeds the mere holding effect of the minor magnet on thearmature.

If the device he appliedin an alternatingcurrent circuit, the said minormagnet will serve a function which for some purposes I have found inpractice to be highly important, to wit: It will prevent the tremblingof the armature 4 from the short alternations in the alternatingcurrent. Whether employed in an alternating-current circuit or adirect-current circuit the minor magnet will also serve to hold thearmature-levere in its open position until the main magnetl has beenenergized up to some desired predetermined voltage, thereby preventingtoo early a lift of the armature-lever 4.- from the main magnet 1 andinsuring a quick lift when the main magnet is energized up to thedesired voltage. As shown, the armature-lever 4 is provided with abail-contact a for cooperation with a pair of mercury-cu p contacts a,located in an auxiliary circuit, one of the conductors of which is shownas sectioned and connected to said contacts a, the said conductor beingmarked a 1 have found such a device highly serviceable inalternating-current circuits where it is desirable to control someauxiliary circuit, like a trip circuit, only upon coincidence of phaseand frequency in the source of current supplying the alternating-currentcircuit. Whether in a direct-current circuit or an alternating-currentcircuit it is of general service in many ways wherever the correspondingfunctions are desired. For example, it is of value for use in automaticswitches,

circuit-breakers, and other forms of circuitcontrollers where somecarefully-timed action is required and a quick movement of thearmature-lever is desired.

Instead of the soft-iron induction-magnet 6, as shown in Fig. 1, theminor magnet may be a coil or electromagnet 9, as shown in Figs. 3 andat, and be either shunt-connected in respect to the main magnet 1, asshown by the conductor 10 in Fig. 3, or be direct-connected in serieswith the main magnet, as shown by the conductor 11 in Fig. 4. When thusproperly connected, the electromagnet 9, if properly proportioned inrespect to the main magnet 1, will serve the same purposes as saidsoft-iron or induction magnet 6. Otherwise stated, the electromagnet maybe employed as the minor magnet, if properly wound and connected inrespect to the main magnet 1. Said winding and connection must be suchthat the magnetic forces in the two magnets will be in step with eachother. I prefer the soft-iron magnet 6 because of its extreme simplicityand oheapness and have found the same perfectly reliable in practice.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is as follows:

1. The combination with a main magnet and its armature-lever, of a minormagnet acting on said armature in opposition to the main magnet, andcoincidently with the action thereon of the main magnet, whereby thearmature is held in engagement with the minor magnet until the mainmagnet attains a predetermined strength, substantially as described.

2. The combination with the main magnet, audits armature-lever, of aminor magnet acting on said armature-lever in opposition to the mainmagnet, coincidently therewith, with the two magnets so arranged thatthe magnetic forces therein will be in step with each other, and theminor magnet will hold the armature in engagement until the main magnetattains a predetermined strength,substantially as and for the purposesset forth.

3. The combination with a main magnet and its armature-lever, of a pieceof soft iron located within the field of said magnet and energizedthereby, in position to act on said armature-lever, in opposition tosaid main magnet coincidently therewith, substantially as and for thepurposes set forth.

t. The combination with an alternatingcurrent circuit, of a main magnettherein, an armature-lever for the same, a minor magnet acting on saidarmature-lever in opposition to said main magnet coincidently therewith,with the two magnets so arranged that they are magnetized from the samecurrent, and the armature is held in engagement with said minor magnetuntil the main magnet attains a predetermined strength, substantially asand for the purposes set forth.

In testimony whereof I afiix my signature,

in presence of two witnesses.

JOHN PEARSON.-

Witnesses:

MABEL M. MoGRonr, F. D. MERCHANT.

